[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
at least 13 nukes have to fix cracked reactor nozzles
FYI
Norm
Andrew Hund wrote:
> Monday December 10, 6:01 pm Eastern Time
>
> By Leonard Anderson
>
> SAN FRANCISCO, Dec 10 (Reuters) - The U.S. Nuclear Regulatory Commission
> has identified 13 atomic reactors that are developing tiny cracks that
> could seriously damage plant equipment and cause lengthy shutdowns for repairs.
>
> The NRC, which licenses and oversees the nation's fleet of 103 nuclear
> plants, doesn't believe the cracks in gear that controls the rate of atomic
> fission in the reactors could release poisonous radiation into the
> atmosphere, said Victor Dricks, a spokesman for the NRC.
>
> Instead, the chief headache is an economic one for the plant owners because
> complex inspections and repairs could idle a reactor -- and shut off sales
> of electricity -- for weeks, according to utility officials. Nuclear plants
> produce about one-fith of the nation's electricity.
>
> The hairline cracks in the reactor heads are believed to be caused by
> stress and corrosion triggered by high temperatures and pressure inside the
> reactors combined with years of producing electricity, according to the NRC.
>
> Akron, Ohio-based FirstEnergy Corp.'s (NYSE:FE - news) 935-megawatt Davis
> Besse nuclear plant in Ohio was one of the 13 units the NRC identified as
> having the cracks or being ``highly susceptible'' to them, said Dricks.
>
> The plant was scheduled to shut in April for refueling and maintenance
> work, but the work was moved up to February at the NRC's request.
> Richard Wilkins, a spokesman for FirstEnergy Nuclear Operations, said the
> company hoped to complete the work in 35 to 40 days.
>
> CRACKS IN REACTOR NOZZLES
>
> The NRC investigation focused on metal alloy nozzles on 69 pressurized
> water reactors. Equipment known as control rods pass through the nozzles
> atop the ``head'' of the reactor.
>
> By raising or lowering rods of neatly stacked cylindrical uranium pellets,
> the control rods regulate the intensity of the atomic reaction taking place
> inside the reactor core.
>
> Pressurized water reactors typically have from 50 to 100 nozzles atop each
> reactor head.
>
> Cracks have appeared in the past along the length of the nozzles, but the
> NRC did not consider they needed immediate attention. Inspections and
> repairs usually were made during routine maintenance outages.
>
> Earlier this year, however, circular cracks around the nozzle width began
> to show up, raising a ``potentially significant'' safety concern, the NRC
> said in a bulletin sent to plant operators in August.
>
> Circular cracks are difficult to find, and plants may need to do
> inspections with the help of fiber optic cameras to pinpoint all of them,
> according to the NRC.
> The regulators' main worry is that a nozzle with circular cracks could
> separate from the reactor head, causing debris to fall into the fuel core
> and rupture cooling tubes and damage other power equipment, in turn
> allowing water to escape from the main plant cooling system.
>
> ``It's like a leak in your car radiator. The system is under high pressure,
> so a break will cause coolant to leak out. You have to shut down the plant
> to find out what's going on,'' said a utility official.
>
> Exelon Nuclear's 786-megawatt Three Mile Island 1 unit in Pennsylvania, one
> of the 13 plants, had to extend a refueling outage expected to be finished
> in mid-November by about three weeks for more work, inspection and tests on
> the nozzles and two steam generators.
>
> Three Mile Island owner AmerGen Energy is a joint venture between Exelon
> Corp. (NYSE:EXC - news), of Chicago, and British Energy Plc (quote from
> Yahoo! UK & Ireland: BGY.L) of Scotland.
>
> The NRC's list also includes Virginia Power Co.'s 800-megawattt Surry 1 and
> 921-megawatt North Anna 2 plants in Virginia. Virginia Power, a unit of
> Richmond, Virginia-based Dominion (NYSE:D - news), is making the repairs,
> Dricks said.
> http://biz.yahoo.com/rf/011210/n10297644_1.html
-
Coalition for Peace and Justice and the UNPLUG Salem Campaign; 321 Barr Ave.,
Linwood, NJ 08221; 609-601-8537 or 609-601-8583 (8583: fax, answer machine);
ncohen12@home.com UNPLUG SALEM WEBSITE: http://www.unplugsalem.org/ COALITION
FOR PEACE AND JUSTICE WEBSITE: http:/www.coalitionforpeaceandjustice.org The
Coalition for Peace and Justice is a chapter of Peace Action.
"First they ignore you; Then they laugh at you; Then they fight you; Then you win.
(Gandhi) "Why walk when you can fly?" (Mary Chapin Carpenter)
************************************************************************
You are currently subscribed to the Radsafe mailing list. To unsubscribe,
send an e-mail to Majordomo@list.vanderbilt.edu Put the text "unsubscribe
radsafe" (no quote marks) in the body of the e-mail, with no subject line.